The pulling compounds are lubricants that are used for lubricating the interface between two relatively moving surfaces where a number of requirements have to be met. The compounds must be essentially chemically and physically inert with respect to the surfaces. The compounds must reduce the force required to move one surface over the other. In addition, the compounds must be in a form that permits the easy application to one or both surfaces.
In the prior art, the pulling compounds were prepared by thickening natural fats and oils and clay or chalk in order to provide sufficient lubrication during pulling an object through a conduit. With the start of the petroleum industry lubricant oils and greases were prepared from heavy petroleum oil fractions. In many applications petroleum lubricants are undesirable. Petroleum lubricants can interact with many organic and inorganic substances such as plastics and rubbers, can be difficult to clean up after application and can be unpleasant to workmen.
In view of the serious drawbacks that petroleum lubricant can have in certain applications, water based lubricants were developed. The use of many different water based lubricants is well known. More specifically, aqueous based compositions of high molecular weight polyalkylene oxide polymers have been prepared for a variety of applications including lubrication. Many other compounds have been used in preparing aqueous lubricants such as various fatty acid soaps, acrylate polymers, waxes, alkylene glycols, guar gum, Irish moss, carboxymethyl cellulose, phenolic and amine-formaldehyde resins, hydrocarbon sulfonic acids, gelatin, polyurethanes, and others.
U.S. Pat. No. 3,227,652 (Ackerman) describes an aqueous lubricant comprising ethylene oxide homopolymer having the average molecular weight about 100,000.
U.S. Pat. No. 3,000,826 (Gililand) describes an aqueous cutting oil composition comprising water as the main constituent, 5 to 40 percent of polyethylene glycol, polypropylene glycol or a mixture thereof, 3 to 18 percent alkali metal nitrite and 2 to 15 percent of a secondary or tertiary alkonol amine.
U.S. Pat. No. 4,378,299 (Alexander) describes a water soluble cable pulling lubricating composition. The composition includes an aqueous solution of from about 1 to 4 percent of a water soluble cellulose derivative such as carboxymethyl cellulose, and from about 0.5 to 2 percent of polyacrylamide. The lubricant may also include a hydroscopic agent such as ethylene glycol to prevent the lubricant from drying out too rapidly in use.
U.S. Pat. No. 4,522,733 (Jonnes) relates to aqueous gel lubricants used during installation of electrical or telephone cable in conduit. The lubricant comprises a major portion of water, a polyelectrolyte acrylate compound, a fatty acid compound and a C.sub.1-6 alcohol.
The known aqueous based pulling compositions suffer certain disadvantages. The compositions are expensive, can be stiff, nonthixotropic, can be hard to handle and apply to the surface, can fail to reduce the coefficient of friction under a broad load range.
It is therefore an object of this invention to provide an improved pulling compositions which are inexpensive, have low coefficient of friction and easy to handle.